Surface areas and volume
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Transcript of Surface areas and volume
SURFACE AREAS
AND VOLUMES
CONTENTSSURFACE AREAS AND VOLUMES OF :-CUBOID CUBECYLINDERCONESPHERE
CUBOIDSURFACE AREA
Area of Rectangle 1 = (lxh) +Area of Rectangle 2 = (lxh) +Area of Rectangle 3 = (lxb) +Area of Rectangle 4 = (lxb) +Area of Rectangle 5 = (bxh) +Area of Rectangle 6 = (bxh) + = 2(lxb) + 2(bxh) + 2(lxh) = 2(lb + bh + lh)
VOLUME
CUBE
Area of square 1 = a x aArea of square 2 = a x aArea of square 3 = a x aArea of square 4 = a x aArea of square 5 = a x aArea of square 6 = a x aSurface Area = Area of all 6 faces = 6a2
SURFACE AREA
VOLUME
CYLINDER
Circumference of a circle = 2πrArea covered by a circle = (2πr) x (h) = 2πrh
CURVED SURFACE AREA
TOTAL SURFACE AREA
Area of curved surface + Area or two circles
= (2πr) + (h) + 2πr2
= 2πr (r + h)
VOLUME
CONECURVED SURFACE AREA
After cutting the cone,Curved Surface area = Area of sectorTherefore, Curved surface area =1/2 (l) (2πr) = πrl
TOTAL SURFACE AREA
Total Surface Area = Curved Surface Area +
Area of bottom Circle
= πrl + πr2
= πr (l + r)
VOLUME
SPHERE
The surface area of a sphere with radius r = 4πr2
SURFACE AREA
The curved surface area of a hemisphere with radius r = 2πr2 and the total surface area = 3πr2
VOLUMEIf we make a cone having radius and height equal to the radius of sphere. Then a water filled cone can fill the sphere in 4 times.
rr
V1
r
V=1/3 πr2h
If h = r then
V=1/3 πr3
V1 = 4V = 4(1/3 πr3)
V1= 4/3 πr3